News

Information : Countermeasures for AIS trouble at Straits of Malacca

To: Our valued customers

1. Guidance:

It is recently reported that our AIS products (JHS-180, JHS-182) become to be in trouble, stating that the status of the other vessels is getting less and finally disappears on the display of the own vessel's AIS, only when she is passing through Straits of Malacca.

2. Trouble cause:

Our survey shows that there is some unknown coastal station who is transmitting the

power in DSC (Channel 70) for AIS channel-management.

This signal affects the "Channel-Management" (the AIS is set up to "Narrow-band") and

the system becomes to be in poor reception condition.

3. Countermeasures:

When the system receives the above "channel-management" signal, the display of this system shows "CH MANAGEMENT CHANGE PLS CHECK TRX CONDITION" and at the same time, the ID error no., "525999999" appears at the display of VHF DSC (CH70) per minute. The place is in "Pulau Pisan"(01-22N, 103-12E), "Batu Berhanti" (01-11.7N, 103-52.5E) or around.

When this error signal is no longer received, you are advised to do the setup of "JHS-180 or 182 AIS CH MANAGEMENT" (see attached.) or to turn off the power of AIS and on again -this enables to receive the signal properly in the system.

*Note: Even the above correction is done during the time that the above error is being appeared every one minute, the system again shows the error, of course.